/Engine/Source/Runtime/Engine/Classes/GameFramework/Pawn.h
Get the controller instigating the damage. If the damage is caused by the world and the supplied controller is nullptr or is this pawn's controller, uses LastHitBy as the instigator.
virtual [AController](API\Runtime\Engine\GameFramework\AController) * GetDamageInstigator ( [AController](API\Runtime\Engine\GameFramework\AController) * InstigatedBy, const [UDamageType](API\Runtime\Engine\GameFramework\UDamageType) & DamageType ) const